Guest Users must use Mattermost with two-factor authentication with Mattermost's own built-in solution.
The built-in solution only offers OTP and not push notification that is standard in Microsoft Authenticator. Approved authentication applications are defined in LSIS, and are Microsoft Authenticator, Google Authenticator, Enpass and Authy.
The guide describes how to set up two-factor authentication with Microsoft Authentication when two-factor authentication is enforced on guest accounts.
On your device, the Microsoft Authenticator app to scan the QR code that displays in Mattermost. First click the Plus sign, select Other (Google, Facebook etc) and Scan QR code (or type the secret).
Enter the MFA Code generated by authenticator app in Mattermost where prompted and click Save. You will then get a confirmation that Multi-factor Authentication Setup is completed.
